Search

BACKGROUND CONTEXT C5 palsy is a well-known complication following cervical laminectomy, however the cause of this complication remains elusive, with many studies providing conflicting reports on prognosis and the impact of specific risk factors. PURPOSE To describe the natural history of and risk factors for C5 palsy after first time cervical laminectomy involving C4 and/or C5, in a large series with a high rate of postoperative palsy. STUDY DESIGN/SETTING This is a retrospective case series. PATIENT SAMPLE Patients undergoing first time cervical laminectomy for degenerative spine pathologies at a single institution between January 2008 and July 2018. Adult patients were included if a complete laminectomy was performed at C4 or C5 for degenerative pathology and pre- and postoperative upright lateral x-rays were performed. OUTCOME MEASURES The primary outcome measure was postoperative C5 palsy, defined as a decrease in strength of at least one point in deltoid and/or biceps within 30 days of operation. The secondary outcome measure was recovery of function. METHODS A retrospective database of patients who underwent posterior cervical spine surgery was created and further focused by utilizing specific Common Procedural Technology (CPT) codes associated with our desired patient population. Patients were excluded from our study if they had inadequate pre- and postoperative imaging, as well as patients with a history of prior cervical spine surgery, concurrent anterior surgery, intradural pathology, spinal tumor, or spinal trauma. Patient history, surgical specifics, and neurologic function were recorded. RESULTS A total of 190 patients were treated by 13 surgeons. 53 (27.9%) developed C5 palsy postoperatively. Of patients with C5 palsy, 40 (75.5%) recovered to baseline strength, 46 (86.6%) had at least grade 4 strength at last follow up, and 4 (7.5%) had strength worse than baseline and motor grade less than 4. Median time to recovery was 2.0 (IQR: 0.18 to 8.24) months. Age, gender, preoperative motor score, number of levels decompressed, smoking history, and comorbidities were not associated with a significant increase in the odds of C5 palsy. Risk of C5 palsy increased by 35% for every additional level fused below C4. CONCLUSION The risk of C5 palsy is increased with instrumentation caudal to C5 in operations addressing degenerative cervical pathology. This should be taken into consideration during operative planning. Overall prognosis of C5 palsy is good; however, incidence of this condition may be greater than previously reported.

The accumulation and propagation of hyperphosphorylated tau (p-Tau) is a neuropathological hallmark occurring with neurodegeneration of Alzheimer’s disease (AD). Extracellular vesicles, exosomes, have been shown to initiate tau propagation in the brain. Notably, exosomes from human-induced pluripotent stem cell (iPSC) neurons expressing the AD familial A246E mutant form of presenilin 1 (mPS1) are capable of inducing tau deposits in the mouse brain after in vivo injection. To gain insights into the exosome proteome cargo that participates in propagating tau pathology, this study conducted proteomic analysis of exosomes produced by human iPSC neurons expressing A246E mPS1. Significantly, mPS1 altered the profile of exosome cargo proteins to result in (1) proteins present only in mPS1 exosomes and not in controls, (2) the absence of proteins in the mPS1 exosomes which were present only in controls, and (3) shared proteins which were upregulated or downregulated in the mPS1 exosomes compared to controls. These results show that mPS1 dysregulates the proteome cargo of exosomes to result in the acquisition of proteins involved in the extracellular matrix and protease functions, deletion of proteins involved in RNA and protein translation systems along with proteasome and related functions, combined with the upregulation and downregulation of shared proteins, including the upregulation of amyloid precursor protein. Notably, mPS1 neuron-derived exosomes displayed altered profiles of protein phosphatases and kinases involved in regulating the status of p-tau. The dysregulation of exosome cargo proteins by mPS1 may be associated with the ability of mPS1 neuron-derived exosomes to propagate tau pathology.

Background Many treatment options for osteoporotic vertebral fractures are available. However, limited and variable findings have been reported on the efficacy of the individual therapies. The objective of the present study was to systematically review the reported data for evidence of efficacy of spinal orthoses for osteoporotic vertebral fractures. Methods A systematic review of the PubMed database was performed. Two reviewers evaluated the studies found for eligibility. Randomized controlled trails (RCTs) and prospective nonrandomized, prospective single-arm, and retrospective comparative studies of the treatment of acute osteoporotic vertebral fractures with spinal orthoses were included. Results A total of 16 studies were included: 5 RCTs, 6 nonrandomized prospective comparative studies, 1 retrospective case-control study, and 4 prospective single-arm studies. Of the 16 studies, 4 (3 single-arm studies and 1 nonrandomized study) provided low-quality evidence that bracing, with or without bedrest, was safe. Also, 1 nonrandomized and 1 single-arm study provided low-quality evidence that bracing improved pain and disability. In addition, 4 studies demonstrated that the use of a rigid brace was equivalent to the use of a soft brace or no brace (2 high-quality RCTs, 2 nonrandomized studies, 1 low-quality RCT). Two nonrandomized and one case-control study demonstrated a benefit of kyphoplasty compared with bracing alone (all low quality). Two RCTs had provided low-quality evidence that bracing was superior to no brace and one nonrandomized study provided low-quality evidence that a dynamic brace was superior to rigid orthosis. Conclusions Limited evidence has suggested the safety of spinal orthoses for the treatment of osteoporotic compression fractures. At present, compelling evidence is not available to suggest that a rigid brace is superior to a soft brace or no brace. Kyphoplasty might be of benefit for select patients.

Background Surgical intervention for type II odontoid fractures is a common treatment strategy when conservative management is not appropriate, such as in significantly displaced fractures. However, displaced fractures may not be easily reduced with instrumentation alone. We present a novel technique, using a “bucket-handle” construct to manually reduce a dorsally displaced type II odontoid fracture, in a patient with failure of previously placed dorsal instrumentation. Methods A 63-year-old woman underwent posterior sublaminar wiring and fixation of a type II odontoid fracture at an outside institution. Several weeks later, she presented with graft dislodgement and increased dorsal displacement and angulation of her fractured dens. After removal of her prior instrumentation and placement of segmental instrumentation, a novel construct was created using components from the instrumentation system and was attached to her cervical 2 (C2) screws. Results Dorsal traction on the C2 pars interarticularis screws allowed for manual reduction of her fracture via a 3-point bending moment. This reduction was secured with an occiput to C6 fixation and fusion. She is clinically and radiographically stable at 3-months follow-up. Conclusions This novel “bucket-handle” construct, used in conjunction with occipitocervical fusion, allowed safe and durable manual reduction of a dorsally displaced and angulated type II odontoid fracture.

Accumulation and propagation of Tau is a neuropathological hallmark of Alzheimer's disease, frontotemporal dementia, and related tauopathies. Extracellular vesicles, especially exosomes, participate in Tau propagation in brain, including those produced by human neurons expressing mutant Tau (mTau). The goal of this study was to define the cargo of these mTau exosomes by proteomics analyses. Findings showed that mTau dysregulates the exosome by acquisition, loss, and up- or downregulation of proteins, resulting in pathogenic exosomes capable of propagating Tau neuropathology., Graphical Abstract Highlights Mutant Tau dysregulates exosome cargo generated by human iPSC neurons. Expression of P301L and V337M mutations of Tau in human iPSC neurons result in recruitment of distinct proteins to exosomes, and absence of control proteins to exosomes. Tau mutations of FTDP-17 result in up- and downregulation of exosome proteins. Altered proteome cargo of mTau exosomes may be involved in Tau pathogenesis in vivo in brain., Accumulation and propagation of hyperphosphorylated Tau (p-Tau) is a common neuropathological hallmark associated with neurodegeneration of Alzheimer's disease (AD), frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), and related tauopathies. Extracellular vesicles, specifically exosomes, have recently been demonstrated to participate in mediating Tau propagation in brain. Exosomes produced by human induced pluripotent stem cell (iPSC)-derived neurons expressing mutant Tau (mTau), containing the P301L and V337M Tau mutations of FTDP-17, possess the ability to propagate p-Tau pathology after injection into mouse brain. To gain an understanding of the mTau exosome cargo involved in Tau pathogenesis, these pathogenic exosomes were analyzed by proteomics and bioinformatics. The data showed that mTau expression dysregulates the exosome proteome to result in 1) proteins uniquely present only in mTau, and not control exosomes, 2) the absence of proteins in mTau exosomes, uniquely present in control exosomes, and 3) shared proteins which were significantly upregulated or downregulated in mTau compared with control exosomes. Notably, mTau exosomes (not control exosomes) contain ANP32A (also known as I1PP2A), an endogenous inhibitor of the PP2A phosphatase which regulates the phosphorylation state of p-Tau. Several of the mTau exosome-specific proteins have been shown to participate in AD mechanisms involving lysosomes, inflammation, secretases, and related processes. Furthermore, the mTau exosomes lacked a substantial portion of proteins present in control exosomes involved in pathways of localization, vesicle transport, and protein binding functions. The shared proteins present in both mTau and control exosomes represented exosome functions of vesicle-mediated transport, exocytosis, and secretion processes. These data illustrate mTau as a dynamic regulator of the biogenesis of exosomes to result in acquisition, deletion, and up- or downregulation of protein cargo to result in pathogenic mTau exosomes capable of in vivo propagation of p-Tau neuropathology in mouse brain.

Context Imbalances in maternal 1-carbon nutrients (vitamin B12, folate) have been shown to be associated with higher offspring cardiometabolic risk markers in India. Objective We examined the hypothesis that low plasma vitamin B12 (B12) and high folate and homocysteine concentrations in the mother are associated with higher hypothalamic–pituitary–adrenal axis (cortisol) and cardiovascular responses during the Trier Social Stress Test for Children (TSST-C) in an Indian birth cohort. Methods Adolescents (n = 264; mean age: 13.6 years), whose mothers’ plasma B12, folate and total homocysteine concentrations had been measured during pregnancy, completed 5-minutes each of public speaking and mental arithmetic tasks in front of 2 unfamiliar “judges” (TSST-C). Baseline and poststress salivary cortisol concentrations were measured. Heart rate, blood pressure, stroke volume, cardiac output, and total peripheral resistance were measured continuously at baseline, during the TSST-C, and for 10 minutes after the TSST-C using a finger cuff; beat-to-beat values were averaged for these periods, respectively. Results Maternal low B12 status (plasma B12 < 150 pmol/L) was associated with greater cortisol responses to stress in the offspring (P < .001). Higher homocysteine concentrations were associated with greater offspring heart rate response (P < .001). After adjustment for multiple comparisons, there were nonsignificant associations between higher maternal folate concentrations and offspring total peripheral resistance response (P = .01). Conclusion Our findings suggest that maternal 1-carbon nutritional status may have long-term programming implications for offspring neuroendocrine stress responses.

Previous research has demonstrated a 'seductive allure' of technical or reductive language such that bad (e.g., circular) explanations are judged better when irrelevant technical terms are included. We aimed to explore if such an effect was observable in relation to a covid-19 vaccinations and if this subsequently affected behavioural intentions to take up a covid-19 vaccine. Using a between subjects design we presented participants (N = 996) with one of four possible types of vignette that explained how covid-19 vaccination and herd immunity works. The explanations varied along two factors: (1) Quality, explanations were either good or bad (i.e., tautological); (2) Language, explanations either contained unnecessary technical language or did not. We measured participants' evaluation of the explanations and intentions to vaccinate. We demonstrate a 'seductive allure' effect of technical language on bad vaccine explanations. However, an opposite 'repellent disdain' effect occurred for good explanations which were rated worse when they contained technical language. Moreover, we show that evaluations of explanations influence intentions to vaccinate. We suggest that misinformation that includes technical language could be more detrimental to vaccination rates. Importantly, however, clear explanatory public health information that omits technical language will be more effective in increasing intentions to vaccinate.

AIM Delayed closure of ileostomy following an anterior resection for rectal cancer in the UK is common. The aims of this study were (i) to investigate the variation in patient pathways between hospitals, (ii) to identify the key learning points from units with the shortest time to closure and (iii) to develop guidance for a pathway to minimize delay in ileostomy closure. METHOD This was a mixed methods study. Thirty-eight colorectal units in the UK completed a short online survey. Nine colorectal units in Wales filled in an additional, expanded version of the survey. Semi-structured interviews were performed with clinicians from the six best performing units in terms of timely ileostomy closure. The optimal pathway suggested is based on the best evidence available and the Association of Coloproctology of Great Britain and Ireland guidelines. RESULTS Qualitative analysis revealed that 5% of units (n = 2) have a local target time for ileostomy closure. Of all units, 90% (n = 34) would consider implementing a pathway if guidelines were developed. In-depth interviews highlighted the importance of a multidisciplinary approach, a dedicated coordinator to facilitate timely booking, and consensus on whether closure should be performed before or after adjuvant chemotherapy. CONCLUSION There is a lack of national guidance in timing of contrast studies and ileostomy closure. Key aspects to consider are better information at consent regarding stoma closure timing, a dedicated person to track patients and the planning of contrast studies at discharge from initial surgery. With a dedicated approach closure of ileostomy within 10-12 weeks is feasible for most units.

ObjectivesTo evaluate feasibility and acceptability of a group-based nature recreation intervention (nature hiking) and control condition (urban hiking) for military Veterans with post-traumatic stress disorder (PTSD).Design and settingA pilot randomised controlled trial conducted in the US Pacific Northwest.ParticipantsVeterans with PTSD due to any cause.InterventionsTwenty-six participants were randomised to a 12-week intervention involving either six nature hikes (n=13) or six urban hikes (n=13).Primary and secondary outcome measuresFeasibility was assessed based on recruitment, retention and attendance. Questionnaires and postintervention qualitative interviews were conducted to explore intervention acceptability. Questionnaires assessing acceptability and outcomes planned for the future trial (eg, PTSD symptoms) were collected at baseline, 6 weeks, 12 weeks (immediately after the final hike) and 24 weeks follow-up.ResultsOf 415 people assessed for eligibility/interest, 97 were interested and passed preliminary eligibility screening, and 26 were randomised. Mean completion of all questionnaires was 91% among those in the nature hiking group and 68% in those in the urban hiking group. Over the course of the intervention, participants in the nature and urban groups attended an average of 56% and 58%, respectively, of scheduled hikes. Acceptability of both urban and nature hikes was high; over 70% reported a positive rating (ie, good/excellent) for the study communication, as well as hike locations, distance and pace. Median PTSD symptom scores (PTSD Checklist-5) improved more at 12 weeks and 24 weeks among those in the nature versus urban hiking group.ConclusionsThis pilot study largely confirmed the feasibility and acceptability of nature hiking as a potential treatment for Veterans with PTSD. Adaptations will be needed to improve recruitment and increase hike attendance for a future randomised controlled trial to effectively test and isolate the ways in which nature contact, physical activity and social support conferred by the group impact outcomes.Trial registration numberNCT03997344.

Summary Left ventricular diastolic function (LVDF) is an important marker of early cardiovascular remodelling, which has not been well summarized in young people with overweight/obesity. Weighted, random‐effects regression was used to determine the strength of associations of both body mass index (BMI) and homeostatic model assessment of insulin resistance (HOMA‐IR) with LVDF measures, adjusting for age and sex. Six databases were searched after PROSPERO registration (CRD42020177470) from inception to July 2020 for studies that compared LVDF between overweight/obesity and control groups aged ≤24 years, yielding 70 studies (9983 individuals). Quality and risk of bias were assessed using NHLBI tools, with scores of good, fair, and poor for 6, 48, and 16 studies, respectively. Increased BMI was associated with worse LVDF in all measures except early mitral inflow deceleration time, with septal early diastolic tissue peak velocity to late diastolic tissue peak velocity ratio having the strongest association (n = 13 studies, 1824 individuals; r = −0.69; P

Background Although instrumented stabilization of pediatric atlanto-occipital dislocation (AOD) has been described in the literature, there is little evidence regarding instrumentation techniques in pediatric patients presenting with both AOD and a cervical fracture. We present a case of a 2-year-old male involved in a motor vehicle collision with an unstable C2 fracture and AOD, treated with an occiput-C4 posterior arthrodesis using a rod, crosslink, and cable construct. Case Description This patient suffered a type III C2 fracture and AOD with 4 mm craniocaudal and 3 mm anterior displacement. In the operating room, 2 cobalt chrome connecting rods (3.5 mm) were connected to 1 another with crosslinks at C2 and C4. These were affixed with suboccipital and sublaminar cables at C1, C2, and C4. At 14 months postoperatively, his spine is clinically and radiographically stable. He has spontaneous movement in all 4 extremities, and remains in a persistent vegetative state because of his underlying central nervous system injury. Conclusions Although there is a breadth of literature investigating instrumentation approaches to pediatric AOD, there is minimal evidence on outcomes of patients presenting with both AOD and cervical fracture. The technique we describe has proven safe and effective for this patient.

OBJECTIVEAtlantoaxial instability is an important cause of pain and neurological dysfunction in patients with Down syndrome (DS), frequently requiring instrumented fusion of the upper cervical spine. This study provides a quantitative analysis of C2 morphology in DS patients compared with their peers without DS to identify differences that must be considered for the safe placement of instrumentation.METHODSA retrospective chart review identified age-matched patients with and without DS with a CT scan of the cervical spine. Three-dimensional reconstructions of these scans were made with images along the axis of, and perpendicular to, the pars, lamina, facet, and transverse foramen of C2 bilaterally. Two of the authors performed independent measurements of anatomical structures using these images, and the average of the 2 raters’ measurements was recorded. Pedicle height and width; pars axis length (the distance from the facet to the anterior vertebral body through the pars); pars rostrocaudal angle (angle of the pars axis length to the endplate of C2); pars axial angle (angle of the pars axis length to the median coronal plane); lamina height, length, and width; lamina angle (angle of the lamina length to the median coronal plane); and transverse foramen posterior distance (the distance from the posterior wall of the transverse foramen to the tangent of the posterior vertebral body) were measured bilaterally. Patients with and without DS were compared using a mixed-effects model accounting for patient height.RESULTSA total of 18 patients with and 20 patients without DS were included in the analysis. The groups were matched based on age and sex. The median height was 147 cm (IQR 142–160 cm) in the DS group and 165 cm (IQR 161–172 cm) in the non-DS group (p < 0.001). After accounting for variations in height, the mean pars rostrocaudal angle was greater (50.86° vs 45.54°, p = 0.004), the mean transverse foramen posterior distance was less (−1.5 mm vs +1.3 mm, p = 0.001), and the mean lamina width was less (6.2 mm vs 7.7 mm, p = 0.038) in patients with DS.CONCLUSIONSPatients with DS had a steeper rostrocaudal trajectory of the pars, a more posteriorly positioned transverse foramen posterior wall, and a narrower lamina compared with age- and sex-matched peers. These variations should be considered during surgical planning, as they may have implications to safe placement of instrumentation.

Objective The objective of the study is to identify specific population groups that may benefit from intraoperative motor evoked potentials (MEP) and to assess positive predictive value (PPV) and negative predictive value (NPV) changes during operation by correlating these with postoperative motor outcomes. Methods We retrospectively reviewed 1,043 consecutive patient cases undergoing spine surgery with and without intraoperative monitoring (IOM) at a single institution from January 1, 2016 to December 31, 2017. Demographic and clinical outcome data were collected at multiple time points. An MEP amplitude decrease of 50% or greater was correlated with a motor deficit for this study. Results On multivariate analysis, patients with coronary artery disease and who received IOM were more likely to experience no new deficit (p=0.047) than those who did not receive IOM. Additionally, patients with hyperlipidemia and coronary artery disease (CAD) were less likely than those without to experience no new deficit (p=0.001 and p=0.02, respectively). MEP accounted for 244 cases, of which 15 had alert MEP criteria but no deficit for a PPV of 21.05% at day 1 post-operation. Day 7-30 PPV declined to 14.29%, and by day 90, there was no association. Conclusion Among patients in our study with CAD, IOM use was associated with significantly better outcomes. Patients with higher intraoperative blood loss, hyperlipidemia, and those with CAD were at increased risk of new neurological deficit. The use of motor evoked potentials was associated with low sensitivity and low PPV.

In univentricular (Fontan) physiology, peripheral and splanchnic vascular tone may be raised to counteract reduced cardiac output (CO) and elevated central venous pressure and thus maintain vital organ perfusion. This could negatively affect the normal cardiovascular response to food ingestion, where mesenteric vasodilation and a concurrent rise in CO are central. We sought to elucidate this using rapid cardiovascular MRI. Thirty fasting subjects (50% controls, 40% women and 60% men) ingested a standardized meal. Responses over ~50 min in mean arterial pressure (MAP), CO, and blood flow in all major aortic branches were measured, and regional vascular impedance (Z(0)) was calculated. Differences from baseline and between groups were assessed by repeated-measures mixed models. Compared with the control group, the Fontan patient group had greater fasting Z(0) of the legs and kidneys, resulting in greater systemic Z(0) and similar MAP. They further had similar blood flow to the digestive organs at baseline, despite larger variation in mesenteric resistance. Postprandially, blood flow to the legs decreased in the control group but not in the Fontan patient group. Increases in CO and superior mesenteric blood flow were similar in both groups, but the celiac response was blunted in the Fontan patient group. No significant differences in MAP responses were observed. In conclusion, alterations in vascular tone to counteract adverse hemodynamics and raised hepatic afterload may blunt vasoreactivity in the legs and the celiac axis in Fontan physiology. Further study is needed to determine whether blunted celiac or mesenteric vasoreactivity is linked to deteriorating hemodynamics and poor prognosis in Fontan patients. NEW & NOTEWORTHY Novel data on cardiovascular physiology in response to a meal in Fontan patients are presented. Using a previously validated dynamic MRI protocol, we demonstrated that the usual increase in cardiac output and the dilation of the superior mesenteric artery are preserved in clinically well Fontan patients. In contrast, vasoconstriction of the legs may have prevented redistribution of blood flow from this region in response to the meal. This may also affect responses to other types of stress. Celiac vasodilation was also absent in Fontan patients. This may be due to abnormal hepatic circulation. The proposed protocol may be used to study Fontan complications secondary to abnormal regional hemodynamics.

To better understand Walter Dandy’s intentions and the historical context of his work on hemispherectomy, the authors reviewed his original 1928 publication. Gliomas were considered incurable at that time. Presuming that the loss of motor function denoted a lack of useful tissue in that hemisphere, he pioneered radical removal of the involved cerebral hemisphere. Of the 5 patients operated on by Dandy, 1 died within 48 hours of hemorrhage because of a displaced vascular clip; 1 died of pneumonia in 2 weeks; 2 died of tumor recurrence, at 3 months and 3.5 years, respectively; and a fifth patient was lost to follow-up beyond the 2nd postoperative week. The authors queried the Thomson Reuters Web of Science and Scopus. A total of 88 papers fulfilled inclusion criteria. Half of these papers (44/88) were published after 2012. Only 11% of papers (10/88) quoted Dandy’s paper accurately; half of them were published before 1997. Most publications (76% [67/88]) quoted Dandy incorrectly, all of them from 1997 and later. In the remaining 11 papers (13%), the accuracy of the quotes was unclear. The authors found a trend toward more accurate citation in earlier papers. Critically reviewing Dandy’s report, with an understanding of the historical context, allows a better understanding of his intentions and the value of his contribution.

Modifiable risk factors affect SARS-CoV-2 infection and mortality raising the possibility that lifestyle modification could play a role. This has not been studied at a global level. We analysed publicly available data from countries reporting COVID-19 cases and deaths. Associations of modifiable risk factors with total cases and excess deaths were determined with and without adjustment for confounders. 4,670,832 cases and 311,384 deaths were reported by 181 countries by 18th May 2020. Wealthier countries had the greatest caseload. Obesity was the primary modifiable risk factor for infection and greater age, male sex, physical inactivity and low salt consumption were associated with excess deaths. Obesity was less influential on mortality than physical inactivity. Globally, obesity confers vulnerability to SARS-CoV-2 infection and physical inactivity likely explains the greater mortality in the obese. High salt consumption may induce reductions in tissue ACE2 expression and subsequently reduce mortality rates.

Objective Screw loosening in fracture fixation poses a clinical risk which may lead to implant failure, particularly in poor bone quality. The objective of this study was to examine the effectiveness of a novel screw retention technology (SRT) for increased screw purchase in a large animal metatarsal fracture model. Study Design This was a biomechanical, radiographic, and histological study utilizing an ovine metatarsal fracture model. Twenty-four sheep metatarsi underwent 3-mm ostectomies and were repaired with a nine-hole plate and 3.5-mm screws placed in oversized 3.5-mm holes to simulate worst case revision surgeries (i.e. no initial screw thread bone contact). Sheep were sacrificed at 3, 6 or 12 weeks (n = 6 each) post-operation. Post-sacrifice, each surgically implanted screw underwent either destructive mechanical testing or histomorphometric analyses. Results Treated metatarsi showed improved screw retention and normal fracture healing. Significant improvement in breakout strength and pullout strength of screws treated with the SRT were found as a function of healing time. Histologically, bone ingrowth at the screw interface was also shown to significantly increase with healing time. Improvements in fracture healing, indicated by an increase in bone fraction and decrease in void space at the osteotomy, were also observed with healing time. Conclusion The results demonstrate the effectiveness of the SRT as a method for improved screw retention in a rescue-screw type scenario.

Designing innovative materials for biomedical applications is desired to prevent surface fouling and risk of associated infections arising in the surgical care patient. In the present study, albumin plastic was fabricated and nitric oxide (NO) donor, S-nitroso-N-acetylpenicillamine (SNAP), was incorporated through a solvent swelling process. The albumin-SNAP plastic was evaluated in terms of mechanical and thermal properties, and bacterial adhesion to the plastic surface. Thermal and viscoelastic analyses showed no significant difference between albumin-SNAP plastics and pure, water-plasticized albumin samples. Bacteria adhesion tests revealed that albumin-SNAP plastic can significantly reduce the surface-bound viable gram-positive Staphylococcus aureus and gram-negative Pseudomonas aeruginosa bacterial cells by 98.7 and 98.5%, respectively, when compared with the traditional polyvinyl chloride medical grade tubing material. The results from this study demonstrate NO-releasing albumin plastic's potential as a material for biomedical device applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1535-1542, 2018.

The absence of evidence-based guidelines for platelet transfusion surrounding invasive neurosurgical procedures leads to uncertainty in management. Multiple studies have illuminated this lack of high quality data, and subsequent reliance on expert opinion. The generally accepted threshold for platelet transfusion has hovered around 100,000/μL.We have conducted a review of available clinical literature to identify any evidence that may support or refute these general guidelines, in an attempt to clarify the need for platelet transfusion in the patient requiring neurosurgical intervention.The available evidence is sparse and of low quality, but suggests that a platelet count100,000/μL is associated with increased risk of hemorrhagic complications. In addition, the acuity of thrombocytopenia, magnitude of decrease in platelet count, and responsiveness to platelet transfusions impact the risk of neurosurgical intervention, and should be taken into account when evaluating a patient's surgical candidacy. Higher quality, prospective studies on the subject are unlikely, given a general lack of clinical equipoise on the subject, and the ethical concerns such a study would present.

Mindfulness is known to decrease psychological distress. Possible benefits in pregnancy have rarely been explored. Our aim was to examine the prospective association of mindfulness with autonomic nervous system function during pregnancy and with later infant social-emotional development. Pregnant women (N=156) completed self-report mindfulness and emotional distress questionnaires, and had their autonomic function assessed in their first and third trimesters, including heart rate (HR), indices of heart rate variability (HRV), preejection period (PEP), and systolic (SBP) and diastolic blood pressure (DBP). The social-emotional development of 109 infants was assessed at 4 months of age. More mindful pregnant women had less prenatal and postnatal emotional distress (p

OBJECTIVEThe authors conducted a study to determine whether a change in T1 tilt results in a compensatory change in the cervical sagittal vertical axis (SVA) in a cadaveric spine model.METHODSSix fresh-frozen cadavers (occiput [C0]–T1) were cleaned of soft tissue and mounted on a customized test apparatus. A 5-kg mass was applied to simulate head weight. Infrared fiducials were used to track segmental motion. The occiput was constrained to maintain horizontal gaze, and the mounting platform was angled to change T1 tilt. The SVA was altered by translating the upper (occipital) platform in the anterior-posterior plane. Neutral SVA was defined by the lowest flexion-extension moment at T1 and recorded for each T1 tilt. Lordosis was measured at C0–C2, C2–7, and C0–C7.RESULTSNeutral SVA was positively correlated with T1 tilt in all specimens. After increasing T1 tilt by a mean of 8.3° ± 2.2°, neutral SVA increased by 27.3 ± 18.6 mm. When T1 tilt was reduced by 6.7° ± 1.4°, neutral SVA decreased by a mean of 26.1 ± 17.6 mm.When T1 tilt was increased, overall (C0–C7) lordosis at the neutral SVA increased from 23.1° ± 2.6° to 32.2° ± 4.4° (p < 0.01). When the T1 tilt decreased, C0–C7 lordosis at the neutral SVA decreased to 15.6° ± 3.1° (p < 0.01). C0–C2 lordosis increased from 12.9° ± 9.3° to 29.1° ± 5.0° with increased T1 tilt and decreased to −4.3° ± 6.8° with decreased T1 tilt (p = 0.047 and p = 0.041, respectively).CONCLUSIONSNeutral SVA is not a fixed property but, rather, is positively correlated with T1 tilt in all specimens. Overall lordosis and C0–C2 lordosis increased when T1 tilt was increased from baseline, and vice versa.

Background: Left ventricular hypertrophy (LVH) is a major risk factor for cardiovascular disease, including heart failure. Although linked to obesity and hypertension, its pathogenesis is multifactorial. Blunted postprandial sympathetic regulation of gut blood flow has been observed in overweight animals and suggested as a promotor of hypertension and LVH. We hypothesized that blunted postprandial superior mesenteric blood flow responses would be more common in overweight humans and associated with increased blood pressure and LVH. Methods: Left ventricular dimensions and hemodynamic responses to a standardized high-calorie liquid meal were measured in healthy adolescents (n=82; 39 overweight/obese) by magnetic resonance imaging. Covariates such as body mass index, blood pressure, Tanner score, and an index of insulin resistance were included in multiple regression models to examine the independent associations of mesenteric flow response with blood pressure status and LVH. Results: Food ingestion increased cardiac output (Δmean, 0.45 [SD, 0.62] L·min −1 ; P =3.8×10 −8 ) and superior mesenteric artery flow (Δmean, 0.76 [SD, 0.35] L·min −1 ; P =4.2×10 −31 ). A blunted mesenteric flow response was associated with increased left ventricular mass (B=−12.7 g·m −2.7 per L·min −1 ·m − 0.92 ; P =6×10 −5 ) and concentric LVH (log likelihood, −9.9; P =0.001), independently of known determinants of LVH, including body mass index. It was also associated with elevated systolic blood pressure (B=−18.0 mm Hg per L·min −1 ·m − 0.92 ; P =0.001), but this link did not explain the association with left ventricular mass. Conclusions: Postprandial mesenteric vascular dysfunction is associated with LVH and hypertension, independently of common risk factors for those conditions. These findings highlight a new, independent marker of cardiovascular risk in the young.

Presenting events in a rhythm has been shown to enhance perception and facilitate responses for stimuli that appear in synchrony with the rhythm, but little is known about how rhythm during encoding influences later recognition. In this study, participants were presented with images of everyday objects in an encoding phase before a recognition task in which they judged whether or not objects were previously presented. Blockwise, object presentation during encoding followed either a rhythmic (constant, predictable) or arrhythmic (random, unpredictable) temporal structure, of which participants were unaware. Recognition was greater for items presented in a rhythmic relative to an arrhythmic manner. During encoding, there was a differential neural activity based on memory effect with larger positivity for rhythmic over arrhythmic stimuli. At recognition, memory-specific ERP components were differentially affected by temporal structure: The FN400 old/new effect was unaffected by rhythmic structure, whereas the late positive component old/new effect was observed only for rhythmically encoded items. Taken together, this study provides new evidence that memory-specific processing at recognition is affected by temporal structure at encoding.

Cardiometabolic (CM) disorders begin earlier than previously thought. Better understanding of drivers of CM risk in the young is needed to address this. Adiposity is an established concern but studies largely rely on indirect markers eg. body mass index (BMI) to assess it. BMI is known to reflect both skeletal size & adiposity. This study aimed to compare effects of BMI with independent effects of liver fat percentage (LFP), fat-free mass (FFM), & subcutaneous (SAT) & visceral (SAT) adipose tissue on CM risk in teenagers. Healthy teens [N=82; Age 13–19y; 39 overwt/obese; 46F/36M] had volumetric magnetic resonance (MR) tissue mapping (neck-to-knee T2*-IDEAL). BMI z-score (WHO age/sex reference; zBMI), systolic BP (SBP), fasting blood (TRIGlyceride; CHOLesterol; HDL; IL6; CRP; white blood cells [WBC]; LEPTIN), & insulin & glucose response [0, 20, 40, 60, 90, 120 & 240 min] to a mixed meal (75g glucose + cream) were assessed. Indices of insulin resistance (HOMA-IR) and sensitivity (MATSUDA-IS) were derived from fasting measures & integrated meal responses, respectively. Independent effects of LFP, FFM, SAT & VAT were tested by conditional regression in a 4 compartment model (4CM). Higher zBMI was positively correlated with TRIG, IL6, CRP, WBC, HOMA-IR, LEPTIN & SBP, & inversely with HDL & MATSUDA-IS (Table). The 4CM showed that SAT was responsible for most of these links but VAT contributed to lower MATSUDA-IS, SAT was positively correlated with CHOL (zBMI was not), & FFM was a significant predictor of HDL, CRP & LEPTIN. It was solely responsible for the association of zBMI with SBP. There were no independent effects of LFP. zBMI was strongly driven by both FFM & SAT, limiting its ability to differentiate effects of skeletal size from those of adiposity. Correlation coefficients BMI TRIG (mmol/L) CHOL (mmol/L) HDL (mmol/L) IL6 (pg/mL) CRP (mg/L) WBC (x109/L) HOMA-IR MATSUDA-IS LEPTIN (ng/mL) SBP (mmHg) Median (IQR) 23.4 (20.3, 29.6) 0.64 (0.52, 1.00) 3.5 (3.2, 4.0) 1.2 (1.0, 1.3) 4.0 (2.6, 6.7) 0.67 (0.22, 1.80) 5.6 (4.7, 7.1) 1.5 (0.8, 2.2) 9.3 (5.5, 12.6) 11.1 (2.1, 24.6) 114 (108, 120) zBMI 0.33§ 0.16 −0.43‡ 0.27¶ 0.69‡ 0.51‡ 0.54‡ −0.48‡ 0.77‡ 0.27¶ LFP 0.18 −0.06 0.18 0.19 0.00 −0.06 0.11 0.23 −0.21 −0.00 0.13 VAT 0.07 0.18 0.08 −0.22 0.09 −0.00 0.12 0.19 −0.35§ −0.08 0.09 SAT 0.89‡ 0.37§ 0.33§ −0.25¶ 0.37§ 0.57‡ 0.45† 0.61‡ −0.44† 0.85‡ −0.10 FFM 0.86‡ 0.04 −0.16 −0.34§ −0.02 0.31¶ −0.01 0.25 −0.25 0.39§ 0.34§ ¶P We found associations of zBMI with CM risk in teens that are usually interpreted as due to adiposity. Although SAT was largely responsible, FFM & VAT were important too & the link between BMI & SBP was due solely to FFM. Associations of CM risk factors with BMI may reflect non-adipose tissue effects & should be interpreted cautiously in the young. Acknowledgement/Funding Alexander Jones is funded by a British Heart Foundation Intermediate Clinical Research Fellowship (FS/18/22/33479)

Introduction Cardiovascular disease (CVD) is more common in women who have had pregnancy complications such as spontaneous pregnancy loss. We used cross-sectional data from the UK Biobank Imaging Enhancement Study to determine whether pregnancy loss is associated with cardiac or vascular remodelling in later life, which might contribute to this increased risk. Methods Pregnancy history was reported by women participating in UK Biobank between 2006 and 2010 at age 40–69 years using a self-completed touch-screen questionnaire. Self-reported pregnancy loss was related to cardiovascular measures collected in those women who had participated in the Imaging Enhancement Study up to the end of 2015. Cardiac structure and function were assessed by magnetic resonance (CMR) steady-state free precession imaging at 1.5 Tesla. Three long axes cines (horizontal, vertical and LV outflow tract) and a complete short axis stack were acquired, covering both ventricles. Tagging was used to measure myocardial strain in basal, midventricular and apical short axes views. Carotid intima-media thickness (CIMT) measurements were taken for both common carotid arteries using a CardioHealth Station. Statistical associations with CMR and carotid measures were adjusted for age, BMI and other cardiovascular risk factors. Results Data were available on 2660 women of whom 113 were excluded because of pre-existing CVD and 8 had no pregnancy information available. Of the remaining 2539, 466 were nulligravid and 2073 had a history of pregnancies, of whom 622 reported at least one pregnancy loss (92% miscarriages and 8% stillbirths) and 1451 reported no pregnancy loss. No significant differences in cardiac or carotid parameters were evident in women who reported pregnancy loss compared to other groups (Table 1). CMR cardiac geometry & CIMT measurements Variable Pregnancy History Adjusted Means ± SE Effect Size (%) 95% CI P LVEDV (ml) Pregnancy Loss 122.2±1.0 0 – – No Pregnancy 124.1±1.4 1.58 (−0.83, 4.05) 0.20 Pregnancy (no loss) 122.2±0.8 0.2 (−1.42, 1.48) 0.97 LVESV (ml) Pregnancy Loss 47.8±0.6 0 – – No Pregnancy 48.0±0.8 0.45 (−3.19, 4.22) 0.81 Pregnancy (no loss) 47.3±0.5 −1.01 (−3.19, 1.22) 0.37 VEF (%) Pregnancy Loss 60.6±0.3 0 – – No Pregnancy 61.0±0.4 0.42 (−0.50, 1.35) 0.37 Pregnancy (no loss) 61.0±0.2 0.43 (−0.14, 0.99) 0.14 LVM (g) Pregnancy Loss 70.6±0.6 0 – – No Pregnancy 70.5±0.8 −0.15 (−2.68, 2.44) 0.91 Pregnancy (no loss) 70.4±0.5 −0.26 (−1.81, 1.30) 0.74 CIMT (μm) Pregnancy Loss 633.3±6.5 0 – – No Pregnancy 619.3±8.4 −2.22 (−5.04, 0.68) 0.13 Pregnancy (no loss) 627.1±4.9 −0.99 (−2.75, 0.81) 0.28 Conclusion Women who self-report pregnancy loss do not have significant differences in cardiac or carotid structure in later life to explain past epidemiological findings of increased cardiovascular risk in this population. This may be because this risk operates through other disease mechanisms or that self-report is not a sufficiently reliable way to identify pregnancy loss, and thereby allocate women into risk groups.

La movilizacion temprana (MT) se define como la implementacion de actividad fisica en pacientes criticamente enfermos entre el segundo y quinto dia de ingreso en la Unidad de Cuidados Intensivos (UCI). La MT se ha descrito como una practica segura, factible y con grandes beneficios a corto y largo plazo. Para implementar un protocolo de MT el equipo multidisciplinario debe identificar y superar las barreras de percepcion para la practica de la misma. Algunas de las barreras mas mencionadas son la falta de equipamiento, la pobre o nula cantidad de guias de practica, la sedacion pediatrica y las ordenes medicas. Objetivo: Describir las barreras dentro de la Unidad de Cuidados Intensivos Pediatricos (UCIP) Diseno: Estudio descriptivo transversal. Metodo: Se aplico un instrumento para identificar las principales barreras a la MT a 28 profesionales que laboraran en la UCIP del Hospital de Especialidades del Nino y la Mujer en Queretaro (HENM), Mexico. Resultados: La unica barrera importante observada para la movilizacion de los pacientes en la UCIP es la ausencia de equipo y mobiliario. Otras barreras pueden ser observadas, mas no descritas, como la carencia de personal fisioterapeutico dentro de la UCIP. Conclusion: La MT es aceptada como una intervencion importante dentro de la UCIP. Si queremos describir completamente las barreras con respecto a la misma, las UCIP deberan ser equipadas de forma adecuada. Seran necesarios mas estudios complementarios para darle seguimiento a la actividad fisica dentro de las terapias intensivas. Early mobilization (EM) is defined as the application of physical activity within the first two to five days of critical illness or injury in an Intensive Care Unit (ICU). EM is proven to be a safe practice; it is also been described as feasible and with great short to long term benefits. In order to implement EM in the ICU the multidisciplinary team must identify and overcome perception barriers. Some of the most mentioned barriers in the pediatric ICU are the lack of equipment, the poor or none practice guidelines, pediatric sedation protocols and physician orders. Objective: Describe the barriers limiting the EM practice in a pediatric intensive care unit (PICU). Design: A transversal descriptive study. Method: A total of 28 professional working in the PICU of the Hospital of Children and Women Specialties in Queretaro, Mexico answered a survey to identify the most important barriers for EM. Results: The only important barrier observed was the lack of equipment perceived by the multidisciplinary team. Other barriers where noticed but not motioned such as the low numbers of physical therapists working in the PICU. Conclusion: EM is accepted as an important part of the treatments involved in the PICU. If we want to completely describe Mexican barriers towards the implementation of EM protocols the ICU must be better equipped. Further studies will be needed in order to have a follow up on the physical activity implemented in Mexican PICUs.

IntroductionCardiovascular disease (CVD) is more common in women who have had pregnancy complications such as spontaneous pregnancy loss. We used cross-sectional data from the UK Biobank Imaging Enhancement Study to determine whether pregnancy loss is associated with cardiac or vascular remodelling in later life, which might contribute to this increased risk.MethodsPregnancy history was reported by women participating in UK Biobank between 2006 and 2010 at age 40-69 years using a self-completed touch-screen questionnaire. Associations between self-reported spontaneous pregnancy loss and cardiovascular measures, collected in women who participated in the Imaging Enhancement Study up to the end of 2015, were examined. Cardiac structure and function were assessed by magnetic resonance (CMR) steady-state free precession imaging at 1.5 Tesla. Carotid intima-media thickness (CIMT) measurements were taken for both common carotid arteries using a CardioHealth Station. Statistical associations with CMR and carotid measures were adjusted for age, BMI and other cardiovascular risk factors.ResultsData were available on 2660 women of whom 111 were excluded because of pre-existing cardiovascular disease and 30 had no pregnancy information available. Of the remaining 2519, 446 were nulligravid and 2073 had a history of pregnancies, of whom 622 reported at least one pregnancy loss (92% miscarriages and 8% stillbirths) and 1451 reported no pregnancy loss. No significant differences in any cardiac or carotid parameters were evident in women who reported pregnancy loss compared to other groups (Table 1).ConclusionWomen who self-report pregnancy loss do not have significant differences in cardiac structure, cardiac function, or carotid structure in later life to explain their increased cardiovascular risk. This suggests any cardiovascular risks associated with pregnancy loss operate through other disease mechanisms. Alternatively, other characteristics of pregnancy loss, which we were not able to take account of, such as timing and number of pregnancy losses may be required to identify those at greatest cardiovascular risk.

Many everyday activities require time-pressured sensorimotor decision making. Traditionally, perception, decision, and action processes were considered to occur in series, but this idea has been successfully challenged, particularly by neurophysiological work in animals. However, the generality of parallel processing requires further elucidation. Here, we investigate whether the accumulation of a decision can be observed intrahemispherically within human motor cortex. Participants categorized faces as male or female, with task difficulty manipulated using morphed stimuli. Transcranial magnetic stimulation, applied during the reaction-time interval, produced motor-evoked potentials (MEPs) in two hand muscles that were the major contributors when generating the required pinch/grip movements. Smoothing MEPs using a Gaussian kernel allowed us to recover a continuous time-varying MEP average, comparable to an EEG component, permitting precise localization of the time at which the motor plan for the responding muscle became dominant. We demonstrate decision-related activity in the motor cortex during this perceptual discrimination task, suggesting ongoing evidence accumulation within the motor system even for two independent actions represented within one hemisphere.

Key points The human stress response activates the autonomic nervous system and endocrine systems to increase performance during environmental challenges. This response is usually beneficial, improving the chance of overcoming environmental challenges, but costs resources such as energy. Humans and other animals are known to adapt their responses to acute stress when they are stimulated chronically, presumably to optimise resource utilisation. Characterisation of these adaptations has been limited. Using advanced imaging techniques, we show that cardiovascular and endocrine physiology, reflective of energy utilisation during acute stress, and energy storage (fat) differ between the sexes when they are exposed to chronic stress. We examine possible evolutionary explanations for these differences, related to energy use, and point out how these physiological differences could underpin known disparities between the sexes in their risk of important cardiometabolic disorders such as obesity and cardiovascular disease. Abstract Obesity and associated diseases, such as cardiovascular disease, are the dominant human health problems in the modern era. Humans develop these conditions partly because they consume excess energy and exercise too little. Stress might be one of the factors contributing to these disease-promoting behaviours. We postulate that sex-specific primordial energy optimisation strategies exist, which developed to help cope with chronic stress but have become maladaptive in modern societies, worsening health. To demonstrate the existence of these energy optimisation strategies, we recruited 88 healthy adults with varying adiposity and chronic stress exposure. Cardiovascular physiology at rest and during acute stress (Montreal Imaging Stress Task), and body fat distribution were measured using advanced magnetic resonance imaging methods, together with endocrine function, cardiovascular energy use and cognitive performance. Potential confounders such as lifestyle, social class and employment were accounted for. We found that women exposed to chronic stress had lower adiposity, greater acute stress cardiovascular responses and better cognitive performance. Conversely, chronic stress-exposed men had greater adiposity and lower cardiovascular responses to acute stress. These results provide initial support for our hypothesis that differing sex-specific energy conservation strategies exist. We propose that these strategies have initially evolved to benefit humans but are now maladaptive and increase the risk of disorders such as obesity, especially in men exposed to chronic stress.

Our brain constantly receives tactile information from the body’s surface. We often only become aware of this information when directing our attention towards the body. Here, we report a study investigating the behavioural and neural response when selecting a target amongst distractor vibrations presented simultaneously to several locations either across the hands or body. Comparable visual search studies have revealed the N2pc as the neural correlate of visual selective attention. Analogously, we describe an enhanced negativity contralateral to the tactile target side. This effect is strongest over somatosensory areas and lasts approximately 200 ms from the onset of the somatosensory N140 ERP component. Based on these characteristics we named this electrophysiological signature of attentional tactile target selection during tactile search the N140-central-contralateral (N140cc). Furthermore, we present supporting evince that the N140cc reflects attentional enhancement of target rather than suppression of distractor locations; the component was not reliably altered by distractor but rather by target location changes. Taken together, our findings present a novel electrophysiological marker of tactile search and show how attentional selection of touch operates by mainly enhancing task relevant locations within the somatosensory homunculus.

The cell-surface attachment protein (Env) of the HERV-K(HML-2) lineage of endogenous retroviruses is a potentially attractive tumour-associated antigen for anti-cancer immunotherapy. The human genome contains around 100 integrated copies (called proviruses or loci) of the HERV-K(HML-2) virus and we argue that it is important for therapy development to know which and how many of these contribute to protein expression, and how this varies across tissues. We measured relative provirus expression in HERV-K(HML-2), using enriched RNA-Seq analysis with both short- and long-read sequencing, in three Mantle Cell Lymphoma cell lines (JVM2, Granta519 and REC1). We also confirmed expression of the Env protein in two of our cell lines using Western blotting, and analysed provirus expression data from all other relevant published studies. Firstly, in both our and other reanalysed studies, approximately 10% of the transcripts mapping to HERV-K(HML-2) came from Env-encoding proviruses. Secondly, in one cell line the majority of the protein expression appears to come from one provirus (12q14.1). Thirdly, we find a strong tissue-specific pattern of provirus expression. A possible dependency of Env expression on a single provirus, combined with the earlier observation that this provirus is not present in all individuals and a general pattern of tissue-specific expression among proviruses, has serious implications for future HERV-K(HML-2)-targeted immunotherapy. Further research into HERV-K(HML-2) as a possible tumour-associated antigen in blood cancers requires a more targeted, proteome-based, screening protocol that will consider these polymorphisms within HERV-K(HML-2). We include a plan (and necessary alignments) for such work.

BACKGROUND CONTEXT Palsy of the fifth cervical nerve (C5) is a well-known complication of cervical laminectomy, occurring in 1-30% of cases. PURPOSE To determine the incidence of C5 palsy after posterior cervical decompression at a single institution. STUDY DESIGN/SETTING Retrospective chart review at a tertiary care academic medical center. PATIENT SAMPLE 214 patients undergoing posterior cervical decompression. OUTCOME MEASURES Development of C5 palsy postoperatively, and recovery of function in patients with new onset C5 palsy. METHODS A retrospective chart review identified patients undergoing first time cervical laminectomy for degenerative spine pathologies at a single institution between January 2008 and July 2018. Patients were included if a complete laminectomy was performed at C4 or C5. Patients with a history of prior cervical spine surgery, concurrent anterior surgery, intradural pathology, spinal tumor, or spinal trauma were excluded. Patient history, surgical specifics, and neurologic function were recorded. RESULTS A total of 214 patients were treated by 15 surgeons; 60 patients (28%) developed C5 palsy postoperatively. Of patients with C5 palsy, 47 (78%) recovered to baseline strength, 87% had at least grade 4 strength at last follow-up, and 4 (7%) had strength worse than baseline and grade less than 3. Mean time to recovery was 8 months (max 7 years). Mean length of follow-up was 22 months [AJ1]. Age, gender, vertebral levels involved, and comorbidities were not associated with a significant increase in risk of C5 stretch, or failure to recover. Fusion including the upper thoracic spine was associated with an increased risk of C5 palsy (38.6% vs 28%; p=0.019). CONCLUSIONS This represents one of the largest reported series of patients with postoperative C5 palsy. Overall prognosis is good, but the risk of C5 injury after first time cervical laminectomy may be higher than most prior reports. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Atlantoaxial instability (AAI) is a common cause of neurologic dysfunction and pain in patients with Down syndrome (DS), frequently requiring instrumented fusion of the upper cervical spine. Despite this, optimal treatment strategy is controversial.A systematic review of the literature was performed according to the Preferred Reporting Items for Systemic Reviews and Meta-Analysis statement to identify patients with AAI and DS were treated with upper cervical spine fusion. Patient demographics, preoperative symptoms, fixation type, and outcome measures including complications, neurologic outcomes, and bony fusion status were gathered for patients in the included publications. Meta-analysis was performed to compare outcomes of different types of fixation constructs.Of the 1191 publications retrieved, 51 met inclusion criteria, yielding 137 patients. Six fixation strategies were identified: noninstrumented (n = 6), wiring (n = 77), wiring with rods (n = 14), screw fixation (n = 33), hook and rod fixation (n = 2), and screw and wire fixation (n = 5). Constructs with screws and rods had greater bony union (P = 0.003) and a lower rate of revision surgery (P = 0.047), loss of reduction or pseudoarthrosis (P = 0.009), halo utilization (P0.001), and early neurologic decline (P = 0.004) compared with wiring alone. Constructs with wires and rods had greater bony union (P = 0.036) than wiring alone.Numerous fixation strategies exist for AAI in patients with DS. Using a combination of screws, rods, and wiring in appropriately selected patients may help reduce the high rate of surgical complications in these patients.